SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5820f76f764b5564e04aa8b6294ec006cd240e8b80fb39e2e1d0cbf6f4f79f7f' 
  AND token = '9zbLpeRIUXh3ixn9xcj25qpB0/TKUPXP5/vaAugjqBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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