SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fdab089ba6d45358d48053fec05002f576289e79357c2f1d796608c6dbede11' 
  AND token = 'NGBr5IQJSCpne91I0Z8vDfRDCyZEVlsspXMYpCBgcRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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