SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02c4c5248f2e118e4d652913f0054dc763152142f313c8c43fc6e05af802e5fa' 
  AND token = 'eNZycT20gOwT6y3Lj5pUw0CQxXhAyYPLKs/4eBU6SdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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