SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed42a5d834f6c29a623165ad9fd86077adf60d10865647b7019fd43199a2822c' 
  AND token = 'kkATh4ZwSMLSBEdBj7389gzfnnURkU80j90Qcy2wkqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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