SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea072ccefecf175caa0b40daffa3a57f1fb07fedb54b8a5dcb2a614d76877379' 
  AND token = '70Cn4NcKfsnu4Mxn+cPq9msPYCSCYLehEVd5wGzHYtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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