SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb9165641ebf50c6d8dc64ed97764f8318bc0182e9f8ee0359f588744d9cbc4' 
  AND token = 'UxngZyVax0fSRhVYjiaMBSNFlJfHeRb7B4qeQtcQb/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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