SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74e4bf4e1bea46ff163ec1e0b1ca0b75e63fd6e4cd3313ce733f82a2b632215e' 
  AND token = 'RKFLnuKl3mHTPy+sB2q5WlQo9OkREtvNPUTdXVezsXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}