SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e05a45ed945dc0157a517617c2843d6e2025a3afd2ac694f5d06c928ea960601' 
  AND token = 'rCfJiDnS/kM4CfL8emAM/LSvf7fTSbltPgDTNCt7iXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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