SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5803790b04f1373aec6317cf991f459ad843fc0baa8f54c015eb30a7d611ad66' 
  AND token = 'gIiCJwxD6FF1usYVTJhqv+P1PfizAKsnO5joFKmOp0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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