SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3fcb8959736f31639438341e34266383e274eeea333383bec659a762ad0b24' 
  AND token = 'sw4QOZ99XmDWiIiNJjkfDtiVqPZbf/0/3spfBf/70zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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