SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c1b52afd2f0721c1a51e12171cf64fa4a003945a1d4b30889aecce991352744' 
  AND token = 'ncKnq2YcNNxcu/ebcncPvA8xNI6qCVAcnVkR509I1gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}