SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c5861183b35b9296c66c45448b467488feabbda6d65c46df594fe140704fb4a' 
  AND token = 'kQfRijrO5C8lnD+kwjbjHfm54lYuSKsdQck+HyXcnkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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