SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe7ea2dad34afddd3817a910ce519f89157a41d7a766dec39b5a79a63c676917' 
  AND token = 'jv+qcXjPoeIDGRq2sM6mVTuc5Fcp2hRpnmbNZIgYDyM=' 
  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"
    }
  }
}