SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '312d4585c2d78aac364f4c5383228ced6a22093d75e1fb339cce03d71fa14651' 
  AND token = 'XPKquHVUavbsuelRJIhEC+6igol3u/D4jaUHB/D1gpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00086

JSON explain

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