SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56cf99d5d51d621238dc541de8a219219849e2a7156da90c0e368c6f10028111' 
  AND token = 'ZIdODHTHldf0k4f94O61Ify4QyeD8ry4Afo1T7yBPIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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