SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8da1ab7d8ebb50bf1004b78ea71bc445d94960ec1810612150a7057423beeb9f' 
  AND token = 'EsMKQMw4BLz1z7ZEMGcDiv5/LRY1ijlVQmyNo3DiNXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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