SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a4a889464a5f0ec49a5ed364d7b7fa3a8d7f080cb8fb097ba5244eeed2e4d398' 
  AND token = '1Vv1IsVfL1wd7HfzUj46E3+GqW+rQKueh/91t+sAfEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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