SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feeba7541cbff803da2a154ae642bccc22e64bf8976c1ee8a65d7b6b57dfe2ce' 
  AND token = 'gFYqdRd1ViOsqVVpV6j9TRIA8EQPadR+fFrUOxiT3c8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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