SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ebc2905da59f775451a0e4eeb2ef327ea7a69917b4703670f2ee79f5da8f1e' 
  AND token = 'yJSs+GkkARZppQhVDEQ11Rjp9Xo32v2F9mWnhD+u0m8=' 
  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"
    }
  }
}