SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0afd1723a84df5b78a6e0ae791d225e83f95b735a161257d65d768e78fce0890' 
  AND token = 'ls+Hp8kqD6w+pfUwo4JyTA530823uKUVjo87FSJvsrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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