SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f832013fb9d1bfb6033a8f2306a1db884e803f6b90eaec5323dfb3dba3d872e' 
  AND token = 'MDzJRHnlCQOGH7mdY1cbUYP7DEdGA0u+h3MzDsuztSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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