SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92bcf0c5c1b1160890023ee98a9dba2edbc5f22135b77525931a8099159f33a0' 
  AND token = 'LVM8goOlG9/M4iVcyUq2caL/dumMF2VF4S5HxAcLSs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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