SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f83fbad96822d01235cd33fb8e70ee5bfccdbf26af340c380a5eac23c0f80c7' 
  AND token = 'q3xxNNCbJL/Oe8fld+pdh59oVEn1zwRiZ4U2OMNQ4ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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