SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aadb7b96ab18877932ebea3cb0abf82644d9eef26f0ace17047ecaa9d623beef' 
  AND token = 'FVVG3kvaH2KuGM5tANesEMTEdCUqarjkNdjiF8IgPR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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