SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe22f046c6c6dce9b6468a806fdb82a87511675479752c55dbe8f8282565c6d3' 
  AND token = 'KjLKZ9+8nloFoKLfPqVxWec7NDsiu1BRJ2jXXGrT/PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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