SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e576eafecfcf59da7c0b6e814ef09fa3a78f856fc7934fe225c1043dca9a0962' 
  AND token = 'vxl8pscTn6SWmSp6WRQuFRTfr3NjWTHusaNsEzXspuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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