SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0c5edf46a01bbc255746a183451ab7b250343b0569eca662356893db9d6136' 
  AND token = 'zu+icWHnz3uz1dL4JT51KEE1mdVGzaLkynXFS4tc4VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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