SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0542696698630cf472ba41cf76057ed2af4fc4c57eed31f4ffed3b0e46b81c8e' 
  AND token = '/jPLbusM7AgyuFpKgrDyKxgO3IMBq22lR2h7DxEHp34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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