SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dacb7eba7fd8f5e3bbe8fde68ec7b45ef96b80966254ae82b2f21e3ac78d347' 
  AND token = 'HVIhaqaJP/4I/TT2mFTIIg0cLXG+oMUOH36gWDLkgyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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