SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4256367b4f0ed41bf248b9f43ab80ccdf1a402442496c22588d7cb30821919a' 
  AND token = 'LVtAoX1RDTm5PtA9Jx2eztpaihR3T7RJQP8X5dh3tWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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