SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0849594e400072ae97b0f96db33735bc17c34968aa78a464bbdc13c0b2be3a' 
  AND token = 'dFefYbH1nlvSB0a3RcnT9pstygopJzgkuA56gyJn8nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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