SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fefa0d628d255624404d34fd8355f0c36942c19c77487acddb5d2573946c6fef' 
  AND token = '6ESDxhPxcYrdauEXnPKvJgt8lgz8CyBEE2Mv3vEbOp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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