SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '236103d89488240839303e0f0fb063f2e8b45c5fb8167cc63515557ee8425e4e' 
  AND token = 'rkEZLExfXCAyxhueuXlrsQFHjBvrNq2ooqQyQhhgeGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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