SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ada1bb662afbb0b8b74a6e811ffecab30b744772be98bf40f722aed26cd7050' 
  AND token = 'DkwMfEWTg32fgQnU0wqGn8lCGOrV3U914qRDgadBJyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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