SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0959bd75a5dc4a136323b6dcfcba12d02c5efb1dee41dc1803cc8a74767aa4f' 
  AND token = 'VrmTyQ6KV6uHGAyC2YRtwcIiEq5ulparIq745AfhjF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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