SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c47aa6b858b933033b568fca6c89fa518809fb2bfb5b82d88758379a157dcda' 
  AND token = 'gpKS3dwMOJVwX5W06cKGYhpD3OUK3ZVB6FZHjjHquH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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