SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3b52baed8dbafb770cae8b3dee7421279be3adc5ab3bf86bfd9780634b65ea7' 
  AND token = 'oxeGYSiLR8gUJdioCfiTJNth93SU04P5hJI2sapoECA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}