SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2786d2ae2a7f91267b765fb130b810dbde01bcdf313fd19342729ea8964f5979' 
  AND token = 'ALqHtawCMC1gcKGf++CMnEiSEwixCTZMXEMYdatRpsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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