SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '937324255e9f3002c59b4cdecff7959c9082657af0f4f08b6cf2bfe6c5d51bcd' 
  AND token = 'rrVcSs9m7T4tso0JVdqaSBqC2PudQ8qLVUeIfJmrrTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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