SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cece0bdfc1c0b7ab74347a37404b6a54b62cfe98e336a176be58346158fcc45d' 
  AND token = 'xobYMcRoKg41lnvQL6/4VU7v94Y6G1Hp8bFw+kh5A84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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