SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb157f6af68d6afecd98dbbd08e28375585a5ef7e87c22b88010d805b3916056' 
  AND token = 'Ew7Qzxe7DPzrsgnp+gkKfAfE8saibNBxsNV0ZdJAgv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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