SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6367ae3cafa2b981bf93dde5e0a69222784640bfa05735edf55e3749369c5c4a' 
  AND token = 'btBAkrNovW42BvCZpXCGykmfPda3JyQsqQqWiWeGK64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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