SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5502f7d83cad0308bc01f742bc03a2a9469bb93918f2fac5d8e694115e50f55f' 
  AND token = 'dqpVkAOVRrQmmnJVtcycRe6Ew9zvrGEtlQnkjtPThzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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