SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d984ecffca4d3d84d8781e1572d6da37a2ceac49dc2517277c35764b782e06' 
  AND token = 'd+QfoSpAYyrYLkuaPJn1aPS56CBdYMiM3nMhuJOcQos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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