SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd00c1d85ff596c39b5a704a75a64712f90e6aab6b41b2baa8b71e40b7441502f' 
  AND token = 'WWIq6MtlYi6qdXHxrNpwdMEoK7zxPjITxhOqpMcTArk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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