SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '439e9982047ce7caed046bc1c6fe2f097be2b59ea4a8692bb269ea8419125645' 
  AND token = 'BfS1kF99Y1MyG+XpOaFIftZRbLYHnfsHKSTBOvL4S50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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