SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15a80a5af745b954d992f09bb1d2091081e3cd574432e6a97b2908b380637064' 
  AND token = 'SLqvJnDLrqDF6jo158YuKbDA/U6yZXK1suGoYoX0644=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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