SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90e2f247885717fff9aa2cace2d019aa8b9ad5534e1d2e5ffb5ccd868cdc31a0' 
  AND token = 'DISp20PCRMwBbLVq9AT+QVzY3h/TzqvGVKmO7NtD6h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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