SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '377575ce1ade0270b5dffff6601b4e1e4d0bd6eed41c24a551a36cfcea29dd79' 
  AND token = 'FPDTZySpDELojYaXI87bSz1DXobquoI15WhXj4/C8SY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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