SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cfccb7d80f7aa068ac0c696687845bbf3221f936fa7e6e38567d44c04c65e2c' 
  AND token = '+3ykbudxjhELrW62TlBHXk/F2Fdhz/svDQIweTWprLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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