SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4cafc3077004a62b1dd9ec23f200e61dc1b137820aad8e9d10b0c407196d32a7' 
  AND token = 'CnwpJwCChRSk6rYJfc+5mu6ZiQgzhqsvCNhuQVwBErs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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