SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '124f5b2e521eb2870086fb17d83117bec581d843135cbec8f134a5ff23a328ca' 
  AND token = 'I3LdK1xK1Bllns8ZVTA6l6JgCJwMhpJD/NY2okpLoHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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