SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26921c4befec62760e39ea3fa4d48aaa2eb0d6b5349759d43791d5782d2a07d7' 
  AND token = 'Dj7OAqMjlqqRnPaR8mEflUmmp4620T10Dru/dQqp8O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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