SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04b528f4218705c1259c9b3119562d94983195390bf0909be585bcd2e376e51' 
  AND token = 'ZbSQYo/lwnr/aJTU3/tOHhJQEQD50YEcncxpcKbKeKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}