SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2b41824dd5909682977e5ad761d966f2ff881b416a3f696c58326d0e6b14f5d' 
  AND token = 'U/k890lm92ZZ8P8aWgtEqrloBjYXcIiVVMUQUuDs4wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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