SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d94756dcaa862fea91d8aeba37ad9a9572c146c186777683ab01c0bf854af2f' 
  AND token = 'kwHmpFhzxXPxofNtlQJMliwhOQZN/UvlXw2x3UcOIKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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