SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2885bfd78a3f64759b6e702370fd314d9877115e42ad3823d95a845b9555c114' 
  AND token = '/lzvMiu+RBPP37w4AWX0+nQKzk7CMQW1uNPn4WUgDvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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