SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9269367a962a7498f5635b4a96ce23f7d879b67b519d42db00e39c970084966' 
  AND token = '/ILpLlbDC2Y0OlmGXbzhvsUkNvSH+b1ZMVnC4al1j6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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