SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f42f7510e683944537d492eca536ab68ebbfb460915a499d159562e6de34cf' 
  AND token = 'oxNgsWqrN2/sLQ8uZVORb3i/nsFyDDY6RYweKjaLlbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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